1. Field of the Invention
This invention relates generally to the splitting of logs and, more particularly, to an apparatus for, method of and system for the automation of log splitting.
The invention contemplates utilization in a high speed, quantity production system of splitting logs for purposes such as firewood. Although the principles of the invention are generally applicable to the splitting of logs at any step in the development of an automated system, the primary advantage to this invention, i.e., speed, is best utilized in a large quantity output situation.
2. Prior Art
There exists a large number of patents which have been issued for log splitting devices of varying designs. Surely, there have been multitudes of designs for log splitters which have reached the public domain without benefit of patent protection.
One of the earliest designs of patented log splitters, issuing around 1907, was typified by an axe-head moving against a support, between the two of which a log is positioned. The log is held in place by means of guide rods at either side of the log. The axe-head is also slideably mounted on the guide rods. U.S. Pat. Nos. 846,838 and 846,839 are concerned with a design such as this.
In 1908, U.S. Pat. No. 885,458 issued on a design basically the same as those immediately above, but with the axe-head stationary and the log support moveably mounted on guide rods.
In all of the patents cited above, the dimensions of the log are extremely important. The diameter is strictly limited on the one hand by the distance between the guide rods and on the other hand by the inability to center a log which is too small.
Further, all of the above patents teach the use of an axe-head blade for cutting the log. This axe-head construction results in a massive wedge-like structure which is required either to be pushed through a log or to have a log pushed through it. Clearly, the force required to do this is great. The design of the above mechanisms are such that the log is not really split, but rather only perforated at one end in hope that the pressure of the hydraulic cylinder will cause the log to crack into portions.
Yet another concept is shown by U.S. Pat. No. 3,596,691, which has a specifically stated purpose of making fencing material. This apparatus has a cutting blade which is forced through a log by chain drive system. The apparatus also includes an elaborate mechanism for causing the log to rotate in order to allow splitting of the log along any diameter. Still further, a mechanism is included to hold the split log together, while turning and splitting at another diameter.
Two other patents, U.S. Pat. Nos. 3,077,214 and 3,280,864, concern a stationary blade with an hydraulically operated log pusher. The former patent includes its own hydraulic pump motor while the later patent contemplates operation in conjunction with an independent pump means, such as a tractor. These apparatus are, of course, limited to the size of log which they will accommodate, although not as exacting as the patents above mentioned. Also, the cutting blade in both of the apparatus are substantially bulky requiring large amounts of hydraulic force as noted with respect to previously mentioned concepts. One further comment is that each log must be hand placed between the blade and the pusher. Also, after splitting, the logs, have fallen from the machine must again be handled manually.
A number of issued patents suggest the use of a four-way blade to simultaneously split a log into four portions. Two examples of this approach are shown by U.S. Pat. Nos. 885,458 and 889,328. The former was discussed above with respect to the basic details. The latter involves a blade slideably mounted on guide rods and mechanically forced against a log in the direction of a fixed support. In both cases, the four-way blade is a massive structure requiring much brute force to even begin to split the log. Even the fact that the former patent mentions the four-way blade only in passing indicates the nonimportance and ineffectiveness of the idea as viewed by the inventor.
In U.S. Pat. No. 2,580,735 a four-way blade is shown which is intended to be forced through a log by a combination of hydraulics and mechanics. The log must, however, be manually loaded and unloaded from the apparatus. The blade is intended to split a log into four portions during the first half of a stroke and return the blade to a start position on the second half of the stroke.
An even more recent concept utilized in the prior art is shown by U.S. Pat. No. 3,319,675. In this apparatus, a double sided blade is used to enable logs to be split as the blade moves in both directions. The blade is attached to a slide and activated by a two-way hydraulic cylinder. Abutments at either end of the slide restrain logs during splitting. The logs must be manually loaded into the splitter and manually maneuvered to either again split the sections or remove the sections upon completion of splitting.
The prior art appears to show no concern for automating the log splitting processes to effect an economic, quantity operation.